Energy storage devices such as lithium ion secondary batteries are used as power supplies of mobile apparatuses such as notebook computers and mobile phones, and the energy storage devices have recently become used as power supplies of electric vehicles in a wide range of fields. Herein, in order to achieve the long-term life of the energy storage device, it is necessary to grasp the deterioration state of the energy storage device, and use the energy storage device in accordance with the deterioration state.
Therefore, it is important to grasp the deterioration state of the energy storage device, and there is conventionally proposed a technology capable of determining the deterioration state of the energy storage device (e.g., refer to Patent Document 1). In this technology, the deterioration state of a secondary battery is determined. In a case where the secondary battery is deteriorated, the deteriorated secondary battery is regenerated.